1. Field of the Invention
This invention is directed to novel compositions comprising one or more nonamantanes. This invention is also directed to novel processes for the separation and isolation of nonamantane components into recoverable fractions from a feedstock containing one or more nonamantane components.
References
The following publications and patents are cited in this application as superscript numbers:
1 Lin, et al., Natural Occurrence of Tetramantane (C22H28), Pentamantane (C26H32) and Hexamantane (C30H36) in a Deep Petroleum Reservoir, Fuel, 74(10):1512-1521 (1995)
2 Alexander, et al., Purification of Hydrocarbonaceous Fractions, U.S. Pat. No. 4,952,748, issued Aug. 28, 1990
3 McKervey, Synthetic Approaches to Large Diamondoid Hydrocarbons, Tetrahedron, 36:971-992 (1980).
4 Wu, et al., High Viscosity Index Lubricant Fluid, U.S. Pat. No. 5,306,851, issued Apr. 26, 1994.
5 Chung et al., Recent Development in High-Energy Density Liquid Fuels, Energy and Fuels, 1.3, 641-649 (1999).
6 Sandia National Laboratories (2000), World""s First Diamond Micromachines Created at Sandia, Press Release, (2/2212000) www.Sandia.pov.
7 Balaban et al., Systematic Classification and Nomenclature of Diamondoid Hydrocarbons-I, Tetrahedron. 34, 3599-3606 (1978).
8 Chen, et al., Isolation of High Purity Diamondoid Fractions and Components, U.S. Pat. No. 5,414,189 issued May 9, 1995.
All of the above publications and patents are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference in its entirety.
2. State of the Art
Nonamantanes are bridged-ring cycloalkanes. They are the face-fused nonamers of adamantane (tricyclo[3.3.1.13,7]decane) or C10H16. The compounds have a xe2x80x9cdiamondoidxe2x80x9d topology, which means their carbon atom arrangement is superimposable on a fragment of the diamond lattice (FIG. 1). Nonamantanes possess nine of the xe2x80x9cdiamond crystal unitsxe2x80x9d and therefore, it is postulated that there are hundreds of possible nonamantane structures which exist in different molecular weight families of possible structures. Among the core structures there are six families of nonamantanes having the following molecular formulas: C42H48 (molecular weight 552), C41H46 (molecular weight 538), C40H44 (molecular weight 524), C38H42 (molecular weight 498), C37H40 (molecular weight 484) and C34H36 (molecular weight 444).
Little or no published work is available for nonamantanes and higher molecular weight diamondoids. Nonamantane compounds have not been artificially synthesized or isolated and these higher diamondoids along with hexamantane, heptamantane and octamantane compounds have been recently thought only to have a theoretical existence.7 Academic chemists have primarily focused research on the interplay between physical and chemical properties in lower diamondoids such as adamantane, diamantane and triamantane. Adamantane and diamantane, for instance, have been studied to elucidate structure-activity relationships in carbocations and radicals.3 Process engineers have directed efforts toward removing lower diamondoids from hydrocarbon gas streams.2 These compounds cause problems during the production of natural gas by solidifying in pipes and other pieces of equipment.
The literature contains little information regarding practical applications of higher diamondoids and even less, if any, information regarding nonamantanes. This fact is probably due to extreme difficulties encountered in their isolation and due to failed synthesis attempts. Lin and Wilk, for example, discuss the possible presence of pentamantanes in a gas condensate and further postulate that hexamantane may also be present.1 The researchers postulate the existence of these compounds contained within petroleum solely based on a mass spectrometric selected ion monitoring (SIM) and mass spectral fragmentation patterns. They did not, however, report the isolation of a single pentamantane or hexamantane nor mention heptamantane, octamantane or nonamantane. Nor were they able to separate non-ionized components during their spectral analysis. McKervey et al. discuss an extremely low-yielding synthesis of anti-tetramantane.3 The procedure involves complex starting materials and employs drastic reaction conditions (e.g., gas phase on platinum at 360xc2x0 C.). Although one isomer of tetramantane, i.e. anti-, has been synthesized through a double homologation route, these syntheses are quite complex reactions with large organic molecules in the gas phase and have not led to the successful synthesis of other tetramantanes. Similar attempts using preferred ring starting materials in accordance with the homologation route, have likewise failed in the synthesis of pentamantanes. Likewise, attempts using carbocation rearrangement routes employing Lewis acid catalysts, useful in synthesizing triamantane and lower diamondoids have been unsuccessful in synthesizing other tetramantanes or pentamantanes. No attempt to synthesize or isolate nonamantanes has been reported.
Among other properties, diamondoids have by far the most thermodynamically stable structures of all possible hydrocarbons that possess their molecular formulas due to the fact that diamondoids have the same internal xe2x80x9ccrystalline latticexe2x80x9d structure as diamonds. It is well established that diamonds exhibit extremely high tensile strength, extremely low chemical reactivity, electrical resistivity greater than aluminum trioxide (Al2O3), excellent thermal conductivity, and superb optical properties.
In addition, based on theoretical considerations, the nonamantanes have sizes in the nanometer range and, in view of the properties noted above, the inventors contemplate that such compounds would have utility in micro- and molecular-electronics and nanotechnology applications. In particular, the rigidity, strength, stability, variety of structural forms and multiple attachment sites shown by these molecules makes possible accurate construction of robust, durable, precision devices with nanometer dimensions. The various nonamantanes are three-dimensional nanometer sized units showing different diamond lattice arrangements. This translates into a variety of rigid shapes and sizes for the nonamantane components. For example, [12121212] nonamantane is rod shaped, [121(2)32(1)3] nonamantane is triangular shaped, while [12342142] is an xe2x80x9cLxe2x80x9d-shaped structure. A variety of other shapes exist among the nonamantanes which may serve in applications which depend upon specific geometries. It has been estimated that MicroElectroMechanical Systems (MEMs) constructed out of diamond should last 10,000 times longer then current polysilicon MEMs, and diamond is chemically benign and would not promote allergic reactions in biomedical applications.6 Again, the inventors contemplate that the various nonamantanes would have similar attractive properties. Furthermore, many of the nonamantanes would possess chirality, offering opportunities for making nanotechnology objects of great structural specificity and ones which have useful optical properties. FIG. 2 illustrates examples of symmetric and asymmetric nonamantane structures. Applications of these nonamantanes include molecular electronics, photonics and production of nonmechanical devices, and other materials.
Notwithstanding these advantages of nonamantanes, the art, as noted above, fails to provide for compositions comprising nonamantanes or for processes that would lead to these compositions. In view of the above, there is an ongoing need in the art to provide for compositions comprising one or more nonamantanes.
This invention is directed to novel compositions comprising one or more nonamantane components.
Accordingly, in one of its composition aspects, this invention is directed to a composition comprising one or more nonamantane components wherein said composition comprises at least about 25 weight percent nonamantane components based on the total weight of the diamondoids in the composition.
In another of its composition aspects, the compositions preferably comprise one or more nonamantane components wherein the nonamantane components make up from about 50 to 100 weight percent, preferably about 70 to I00 weight percent, more preferably about 90 to 100 weight percent and even more preferably about 95 to 100 weight percent of the total weight of the diamondoids in the compositions.
In another of its composition aspects, the compositions comprise at least about 10 weight percent and preferably at least about 20 weight percent of nonamantanes based on the total weight of the composition. Other compositions of this invention contain from 50 to 100 weight percent, 70 to 100 weight percent, 95 to 100 weight percent and 99 to 100 weight percent of nonamantanes based on the total weight of the composition.
In another of its composition aspects, the compositions preferably comprise from about 70 to 100 weight percent, more preferably from about 90 to I 00 weight percent, even more preferably from about 95 to 100 weight percent and most preferably from about 99 to 100 weight percent of a single nonamantane component, including isolated optical isomers thereof, based on the total weight of the composition
This invention is also directed to novel processes for the separation and isolation of nonamantane components into recoverable fractions from a feedstock containing one or more nonamantane components and nonnonamantane materials. These processes for recovering a composition enriched in nonamantane components entail removing at least a portion of the nonnonamantane materials which have a boiling point below the lowest boiling nonamantane component and utilizing a subsequent separation technique to recover nonamantane components from the resulting residue. Accordingly, this aspect is directed to processes which comprise:
a) selecting a feedstock comprising recoverable amounts of nonamantane components and nonnonamantane materials;
b) removing from the feedstock a sufficient amount of nonnonamantane materials that have boiling points below the boiling point of the lowest boiling point nonamantane component in the feedstock under conditions to form a treated feedstock enriched in nonamantane components which can be recovered;
c) recovering nonamantane components by separating said treated feedstock formed in b) above with one or more additional separation techniques selected from the group consisting of chromatographic techniques, thermal diffusion techniques, zone refining, progressive recrystallization and size separation techniques.
In a preferred embodiment, after the step recited in b) the treated feedstock can be thermally treated to pyrolyze at least a sufficient amount of nondiamondoid components therefrom under conditions to provide a thermally treated feedstock retaining recoverable amounts of nonamantane. Such a pyrolization step prior to step c) is useful for thermally degrading at least a portion of any materials remaining in the treated feedstock having a thermal stability lower than the nonamantane components. This pyrolysis step can be carried out before step b) if desired.
In a preferred embodiment of this invention, directed to the chromatographic techniques, is employing high performance liquid chromatography using one or more columns, more preferably reverse phase. A more preferred method, is using columns exhibiting a different selectivity to the nonamantane components slated for enrichment. Alternatively, high performance liquid chromatography can be coupled with gas chromatography, such as preparative gas chromatography to further facilitate isolations.